I too modified the A14/15 gaskets and yes they were quite thin at the top but I never had any issues. The GX heads I have are plugged and I've since gone to the Nissan Competition gasket. It may be possible to cut out the holes in the comp gasket. Probably just as easy to order a couple of gaskets from B projects.

Tom

H89 wasn't sold here either ... but during the 1980s/1990s they sent over container loads of 'good used Japanese engines', so sometime you'll find one!

Before you plug the coolant ports, be aware that it will cause part-throttle performance to suffer a little bit. GX doesn't have a heat riser, so it won't combust perfectly unless the coolant passage work. But mid-throttle and full-throttle will work fine

I didn't know the GX was not sold in normal fashion in the US. Makes the junkyard finds of the rare imported ones that much more special. My H89 head is ported to match the GX intake and enlarging a Fel-pro A14 gasket opening leaves it too thin at the top for my comfort. Also, it's hard to do without making a mistake, for me at least. I think I will go with the Bprojects one and plugify the coolant ports. Thanks for the help.

NAPA sells gasket material. You can punch/chisel a gasket out of this gasket stock

Or, buy an A14 manifold gasket, then chisel the ports bigger before installing. This works if you find a gasket without metal-rimmed intake ports -- and one that goes above the ports far enough to enlarge to the GX size

Or, get the Nismo/Nissan Competition gasket and punch out water holes. Use a bit of RTV around the water port holes
Bprojects $13

Nissan common A14 gasket



GX gaskets

The oldest GX gasket had water holes for the original GX intake manifold. BProjects is selling a racing gasket for aftermarket manifolds

GX was never sold in USA, so gaskets are not commonly available. Nissan Competition sold them

Bprojects JAPAN sells a dual bolt pattern manifold gasket without water ports on Ebay. Other GX gaskets won't work with my later style intake. Any other sources for a gasket with water port openings? Not finding anything at Rack Auto or via the online Fel-Pro catalog. I'll buy the Bprojects gasket and plug the holes if I need to, but I wanted to ask first.